subscribe · 19hz MCP: Risk & Policy

SERVER19hz SOURCEhttps://gateway.pipeworx.io/19hz/mcp

Medium RISK CLASS

Category Write

Parameters 32 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-github-pipeworx-io-19hz/subscribe.md

WHAT IT DOES

What subscribe does on 19hz

AI agents use subscribe to create or update resources in 19hz, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your 19hz environment.

Parameter	Type	Required	Description
`type`	string	Yes	Subscription type.
`params`	object	Yes	Type-specific filter. sec_8k: {ticker:"AAPL", items?:["5.02","1.01"]}. polymarket_edge: {topic:"fed", min_spread_bps?:500}. fred_series: {series_id:"UNRATE"}. p
`delivery`	object	—	Optional delivery channels in addition to the always-on persistent feed. {email:"you@x.com"} sends a templated alert per fired event. {sms:"+15551234567"} sends

Parameters from the server's own tool schema.

RISK

Why subscribe is rated Medium

This tool creates and persists a new subscription resource (Write category), which is a reversible state change. The user can later delete or modify the subscription. The severity is medium because misuse could lead to unwanted monitoring and email notifications being set up on behalf of a user, potentially exfiltrating alerts to an attacker-controlled email address or creating spam/resource exhaustion.

From the tool's definition Create a proactive monitoring subscription to a live-data event stream. Returns the new subscription id. ... Requires a Pipeworx OAuth account ... Supported types: 'sec_8k', 'polymarket_edge', 'fred_series'. Delivery channels: feed ... and optionally email.

Risk signalsAccepts URL/endpoint input (delivery.webhook)

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs subscribe safely

PolicyLayer is an MCP gateway: it sits between your AI agents and 19hz, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For subscribe, this is the rule to start with:

subscribe Rate-limited

subscribe stays usable, but capped: an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "subscribe": {
      "limits": [
        {
          "counter": "subscribe_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect 19hz, apply this rule, and every subscribe call is checked against it from then on.

FAQ

Questions about subscribe

What does the subscribe tool do? +

Create a proactive monitoring subscription to a live-data event stream. Returns the new subscription id. Requires a Pipeworx OAuth account (anonymous + BYO cannot persist subscriptions). Supported types: "sec_8k" (8-K filings matching ticker + item codes — e.g. items:["5.02"] = officer change), "polymarket_edge" (Polymarket↔Kalshi cross-venue mispricings — params:{topic:"fed"}), "fred_series" (new FRED observations — params:{series_id:"UNRATE"}). Delivery channels: feed (always on — pull via recent_alerts or GET registry.pipeworx.io/alerts.json), and optionally email (set delivery:{email:"you@x.com"}) or sms (delivery:{sms:"+15551234567"} — phone must be verified at /account first; 10/day cap). It is categorised as a Write tool in the 19hz MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

What parameters does subscribe accept? +

subscribe accepts 3 parameters: type, params, delivery. Required: type, params. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on subscribe? +

Register the 19hz MCP server in PolicyLayer and add a rule for subscribe: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches 19hz. Nothing to install.

What risk level is subscribe? +

subscribe is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit subscribe? +

Yes. Add a rate_limit block to the subscribe rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block subscribe completely? +

Set action: deny in the PolicyLayer policy for subscribe. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides subscribe? +

subscribe is provided by the 19hz MCP server (https://gateway.pipeworx.io/19hz/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

More on 19hz, and thousands of servers like it.

This server

All 32 19hz tools →

Across the catalogue

The MCP Attack Database →

Guides

Govern customer-ops agents →Argument validation →Scoped token →